<?php

/*
 *  Copyright (C) 2010 Emanuele Colonnelli <emanuele.colonnelli@phpstruct.com>
 * 
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 * 
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 * 
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

namespace org\phpstruct\core;

use org\phpstruct\core\driver\cache;
use org\phpstruct\core\i;

/**
 * Description of Cache
 *
 * @author Emanuele Colonnelli <emanuele.colonnelli@phpstruct.com>
 */
class CacheFactory {
  const SESSION = 'Session';
  const MEMCACHE = 'Memcache';

  private static $instance;

  private function __construct() {
	self::$instance = $this;
  }

  /**
   * @return CacheFactory
   */
  public static function getInstance() {
	return (self::$instance instanceof CacheFactory) ? self::$instance : new self();
  }

  public static function getKey($strkey) {
	if (is_null($strkey) || empty($strkey)) {
	  throw new \Exception(Error::E_CACHE_NULL_KEYSTRING(), Error::E_CACHE_NULL_KEYSTRING, null);
	}
	$class = get_called_class();
	$bt = array_shift(debug_backtrace(true));

	$key = md5($bt['class'] . $bt['function'] . \implode('', $bt['args']) . $strkey);

	return $key;
  }

  /**
   *
   * @param <type> $driver
   * @return i\iCache
   */
  public function factory($driver) {
	switch ($driver) {
	  default:
	  case self::SESSION:
		return new cache\Session();
		break;
	  case self::MEMCACHE:
                return new cache\Memcache();
		break;
	}
  }

}
